In a national survey of CFOs and senior comptrollers conducted by Grant Thornton, a consultancy, 64 percent of public companies do not currently report financial results using XBRL, and of those, half have no plans to meet the 2011 deadline to report using interactive data. Many of those companies will likely comply eventually, but that means that IT will be scrambling to implement a new and complex system (unless their companies decide to outsource the work, of course).

Even companies that do move to XBRL will keep its use to the legally required minimum. The number of companies that plan to deploy XBRL for internal reporting (for which there is no mandate) is just 5 percent, according to a poll of CFOs by Gartner.

There are also significant questions about the accuracy of XBRL tagging. Last year, researchers at North Carolina State University studied results [PDF] of a voluntary tagging program and found "a large number of errors and inconsistencies with submissions."

Although there have been modifications and improvements to the XBRL taxonomies and tagging software since that time, the authors warn that their research gives evidence that "the tagging process is difficult and that unacceptable error rates may occur in the future."

XBRL tags provide a common definition for financial terms. While terms like "revenue" and "income" are used broadly, organizations define them differently. But when the definitions are standardized, financial forms will be machine-readable without the current laborious and subjective conversion process. What's more, the data becomes interactive, making it much easier for investors and regulators to analyze it. That's a key reason for the mandate.

But part of the reluctance to move to XBRL is the laborious process of tagging. A typical quarterly financial filing uses 500 to 700 discrete tags, says Patrick Quinlan, CEO of Rivet Software, which provides software and services related to XBRL conversion. An annual report, he adds, could include 4,000 to 5,000 discrete tags.

However, once a series of documents is tagged, subsequent tagging becomes much simpler because the same terms are used over and over again, Quinlan says. If that's true, it's possible that some companies have succeeded in scaring themselves into believing that XBRL is simply too complex to manage.

San Francisco journalist Bill Snyder writes frequently about business and technology. He writes the Tech's Bottom Line blog for InfoWorld, and his work appears regularly in CIO.com and the publications of Stanford's Graduate School of Business and the Haas School of Business at the University of California at Berkeley.